diff --git a/.gitignore b/.gitignore
index 6bad88c..d8d3e42 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@ node_modules
 /.idea/
 /packages/sdk/dist/
 /packages/accounts/dist/
+/yarn-error.log
diff --git a/packages/accounts/package.json b/packages/accounts/package.json
index b738a39..e71b9f1 100644
--- a/packages/accounts/package.json
+++ b/packages/accounts/package.json
@@ -6,6 +6,9 @@
     "clean": "rm -rf dist"
   },
   "version": "0.1.0",
-  "main": "index.js",
-  "license": "MIT"
+  "main": "./dist/index.js",
+  "license": "MIT",
+  "dependencies": {
+    "permissionless": "^0.3.2"
+  }
 }
diff --git a/packages/accounts/src/MultiChainSmartAccount.ts b/packages/accounts/src/MultiChainSmartAccount.ts
new file mode 100644
index 0000000..29b8fa5
--- /dev/null
+++ b/packages/accounts/src/MultiChainSmartAccount.ts
@@ -0,0 +1,117 @@
+import { SmartAccount } from 'viem/account-abstraction'
+import { Call, Hex, LocalAccount, } from 'viem'
+import {
+  asCall,
+  BaseMultichainSmartAccount,
+  FunctionCall,
+  ICrossChainSdk,
+  MultichainBundlerManager,
+  UserOperation
+} from '@eil-protocol/sdk'
+import { toSimpleSmartAccount } from 'permissionless/accounts'
+
+/**
+ * a simple MultichainAccount. using SimpleSmartAccount on each chain.
+ * Note that the signature method called for each SimpleSmartAccount instead separately.
+ * Also, its encoding can't support dynamic calls.
+ */
+export class MultiChainSmartAccount extends BaseMultichainSmartAccount {
+
+  accounts: Map<bigint, SmartAccount> = new Map()
+
+  /**
+   * Creates a new MultiChainSmartAccount instance
+   * @param owner - The account owner used for multichain signing. Must belong to the same owner across all chains.
+   * @param sdk - the sdk configuration to read supported network
+   * @param accounts - Array of {@link SmartAccount} instances for different chains (optional).
+   * @notice The owner must have signing capabilities for all chains.
+   * @dev Note that SimpleAccount API doesn't expose the owner directly.
+   */
+  protected constructor (
+    readonly owner: LocalAccount,
+    sdk: ICrossChainSdk,
+    accounts: SmartAccount[]
+  ) {
+
+    const bundlerManager = new MultichainBundlerManager(sdk.getNetworkEnv().input.chainInfos)
+    super(bundlerManager)
+    this.addAccounts(accounts)
+  }
+
+  static async create (
+    owner: LocalAccount,
+    sdk: ICrossChainSdk,
+    accounts?: SmartAccount[]
+  ): Promise<MultiChainSmartAccount> {
+    const networkEnv = sdk.getNetworkEnv()
+    if (accounts == null) {
+      accounts = []
+      for (const chain of networkEnv.input.chainInfos) {
+        let client = networkEnv.chains.clientOn(chain.chainId)
+        const entryPointAddress = networkEnv.entrypoints.addressOn(chain.chainId)
+
+        const factoryAddress = '0x2862B77afcF4405e766328E697E0236b9974b8fa' //ep9 simpleAccount factory
+        const account: SmartAccount = await toSimpleSmartAccount({
+          owner,
+          client,
+          entryPoint: {
+            address: entryPointAddress,
+            version: '0.8'
+          },
+          factoryAddress
+        })
+        accounts.push(account)
+      }
+    }
+    return new MultiChainSmartAccount(
+      owner,
+      sdk,
+      accounts
+    )
+  }
+
+  //add chain-specific instances of the account.
+  //TODO: currently needs viem "SmartAccount" for each chain. better unify it
+  // (some methods are chain-specific, like "getNonce". others (like encode) are not.
+  protected addAccounts (accounts: SmartAccount[]) {
+    for (const account of accounts) {
+      const chainId = BigInt(account.client.chain?.id!)
+      if (this.accounts.has(chainId)) {
+        throw new Error(`Account object already exists for chainId: ${chainId}`)
+      }
+      this.accounts.set(chainId, account)
+    }
+  }
+
+  hasAddress (chainId: bigint): boolean {
+    return this.accounts.has(chainId)
+  }
+
+  contractOn (chainId: bigint): SmartAccount {
+    if (!this.accounts.has(chainId)) {
+      throw new Error(`No account found for chainId: ${chainId}`)
+    }
+    return this.accounts.get(chainId)!
+  }
+
+  async signUserOps (userOps: UserOperation[]): Promise<UserOperation[]> {
+    // naive implementation: sign using each per-chain account.
+    const result: UserOperation[] = []
+    for (const userOp of userOps) {
+      const chainId = userOp.chainId
+      if (chainId == null) {
+        throw new Error(`signUserOps: can only sign userOps with chain`)
+      }
+      const account = this.contractOn(chainId)
+      const signature = await account.signUserOperation(userOp as any)
+      result.push({ ...userOp, signature })
+    }
+    return result
+  }
+
+  async encodeCalls (chainId: bigint, calls: Array<Call | FunctionCall>): Promise<Hex> {
+    const plainCalls: Call[] = calls.map(call => asCall(chainId, call))
+    return this.contractOn(chainId).encodeCalls(plainCalls)
+  }
+}
+
diff --git a/packages/accounts/src/index.ts b/packages/accounts/src/index.ts
index 5ac8a03..2559b60 100644
--- a/packages/accounts/src/index.ts
+++ b/packages/accounts/src/index.ts
@@ -1 +1,2 @@
-console.log('accounts')
+export * from './ambire/AmbireMultiChainSmartAccount.js'
+export * from './MultiChainSmartAccount.js'
diff --git a/packages/sdk/src/sdk/CrossChainSdk.ts b/packages/sdk/src/sdk/CrossChainSdk.ts
index 14bd43c..62b936b 100644
--- a/packages/sdk/src/sdk/CrossChainSdk.ts
+++ b/packages/sdk/src/sdk/CrossChainSdk.ts
@@ -1,7 +1,6 @@
-import { CrossChainConfig } from './config/index.js'
-import { ICrossChainBuilder, ICrossChainSdk, IJsonRpcProvider } from './types/index.js'
-import { CrossChainBuilder, InternalConfig } from './builder/index.js'
-import { IMultiChainSmartAccount } from './account/index.js'
+import { CrossChainConfig, defaultCrossChainConfig } from './config/index.js'
+import { AddressPerChain, ICrossChainBuilder, ICrossChainSdk, MultichainToken } from './types/index.js'
+import { CrossChainBuilder, NetworkEnvironment } from './builder/index.js'
 
 /**
  * This class is the main component for building cross-chain actions.
@@ -9,21 +8,30 @@ import { IMultiChainSmartAccount } from './account/index.js'
  */
 export class CrossChainSdk implements ICrossChainSdk {
 
-  config: InternalConfig
+  networkEnv: NetworkEnvironment
 
   constructor (
-    readonly account: IMultiChainSmartAccount,
-    config: CrossChainConfig,
-    readonly walletProvider: IJsonRpcProvider | undefined = undefined
+    config: CrossChainConfig = defaultCrossChainConfig
   ) {
-    this.config = new InternalConfig(config)
+    this.networkEnv = new NetworkEnvironment(config)
   }
 
   /**
    * create a builder for a cross-chain operation
    */
   createBuilder (): ICrossChainBuilder {
-    return new CrossChainBuilder(this.config, this.account)
+    return new CrossChainBuilder(this.networkEnv)
+  }
+
+  /**
+   * create a MultichainToken with the given deployment addresses
+   */
+  createToken (name: string, deployments: AddressPerChain): MultichainToken {
+    return new MultichainToken(name, this.networkEnv.chains, deployments)
+  }
+
+  getNetworkEnv (): NetworkEnvironment {
+    return this.networkEnv
   }
 }
 
diff --git a/packages/sdk/src/sdk/actions/VoucherRequestAction.ts b/packages/sdk/src/sdk/actions/VoucherRequestAction.ts
index ed39586..b8afb45 100644
--- a/packages/sdk/src/sdk/actions/VoucherRequestAction.ts
+++ b/packages/sdk/src/sdk/actions/VoucherRequestAction.ts
@@ -1,7 +1,7 @@
 import { Address, Call } from 'viem'
 
 import { BaseAction, BatchBuilder, FunctionCall, SdkVoucherRequest, toAddress } from '../index.js'
-import { NATIVE_ETH } from '../types/Constants.js'
+import { NATIVE_ETH } from '../types/index.js'
 
 /**
  * The internal class defining an action to lock the user deposit for the specified {@link SdkVoucherRequest}.
diff --git a/packages/sdk/src/sdk/builder/BatchBuilder.ts b/packages/sdk/src/sdk/builder/BatchBuilder.ts
index cc5586c..5553689 100644
--- a/packages/sdk/src/sdk/builder/BatchBuilder.ts
+++ b/packages/sdk/src/sdk/builder/BatchBuilder.ts
@@ -1,9 +1,10 @@
-import { Address, Hex, PrivateKeyAccount, publicActions } from 'viem'
+import { Address, Hex, hexToBigInt, PrivateKeyAccount, publicActions } from 'viem'
 import { BaseAction, FunctionCallAction, prepareCallWithRuntimeVars, VoucherRequestAction } from '../actions/index.js'
 import { CrossChainBuilder } from './CrossChainBuilder.js'
 import { CrossChainVoucherCoordinator } from './CrossChainVoucherCoordinator.js'
-import { InternalConfig } from './InternalConfig.js'
+import { NetworkEnvironment } from './NetworkEnvironment.js'
 import {
+  ICrossChainBuilder,
   InternalVoucherInfo,
   isCall,
   isValidAddress,
@@ -15,9 +16,8 @@ import {
 } from '../types/index.js'
 import { appendPaymasterSignature, getUserOpHash } from '../index.js'
 import { assert } from '../sdkUtils/SdkUtils.js'
-import { IMultiChainSmartAccount } from '../account/index.js'
 import { Asset } from '../../contractTypes/Asset.js'
-import { abiEncodePaymasterData } from '../../utils/index.js'
+import { abiEncodePaymasterData, nowSeconds } from '../../utils/index.js'
 
 /**
  * Return the minimum amount for an asset.
@@ -56,14 +56,18 @@ export class BatchBuilder {
   private _vars: Set<string> = new Set()
 
   constructor (
+    private readonly parentBuilder: ICrossChainBuilder,
     private readonly ephemeralSigner: PrivateKeyAccount,
     private readonly coordinator: CrossChainVoucherCoordinator,
-    readonly config: InternalConfig,
-    private readonly smartAccount: IMultiChainSmartAccount,
+    readonly config: NetworkEnvironment,
     readonly paymaster: `0x${string}`,
     readonly chainId: bigint
   ) {}
 
+  endBatch (): ICrossChainBuilder {
+    return this.parentBuilder
+  }
+
   /**
    * Add a new dynamic runtime variable to the batch.
    * Variables can be used to store values that are not known at the time of batch creation.
@@ -127,7 +131,7 @@ export class BatchBuilder {
     } else {
       assert(req.sourceChainId == this.chainId, `Voucher request sourceChainId ${req.sourceChainId} does not match batch chainId ${this.chainId}`)
     }
-    assert(!this.coordinator.has(req), `Voucher request ${req} already exists in this BatchBuilder`)
+    assert(!this.coordinator.has(req), `Voucher request ${req.ref} already exists in this BatchBuilder`)
 
     req.tokens.forEach(token => {
       if (!isValidAddress(req.sourceChainId!, token.token)) {
@@ -138,7 +142,7 @@ export class BatchBuilder {
       }
     })
 
-    this.coordinator.set(req, {
+    this.coordinator.set({
       voucher: req,
       sourceBatch: this,
     })
@@ -155,13 +159,14 @@ export class BatchBuilder {
   /**
    * Use the {@link SdkVoucherRequest} created in an earlier batch to move tokens to this chain.
    */
-  useVoucher (voucher: SdkVoucherRequest): this {
+  useVoucher (refId: string): this {
     this.assertNotBuilt()
-    const internalVoucherInfo = this.coordinator.getVoucherInternalInfo(voucher)
-    assert(internalVoucherInfo != null, `Voucher request ${voucher} not found in action builder`)
+    const internalVoucherInfo = this.coordinator.getVoucherInternalInfo(refId)
+    const voucher = internalVoucherInfo?.voucher!
+    assert(internalVoucherInfo != null, `Voucher request ${refId} not found in action builder`)
     assert(this.userOpOverrides?.paymaster == null && this.userOpOverrides?.paymasterData == null,
       `Cannot override paymaster or paymasterData in a batch that uses vouchers.`)
-    assert(internalVoucherInfo.destBatch == undefined, `Voucher request ${voucher} already used`)
+    assert(internalVoucherInfo.destBatch == undefined, `Voucher request ${refId} already used`)
     assert(voucher.destinationChainId == this.chainId,
       `Voucher request is for chain ${voucher.destinationChainId}, but batch is for chain ${this.chainId}`)
     internalVoucherInfo.destBatch = this
@@ -179,7 +184,7 @@ export class BatchBuilder {
     for (const v of allVoucherRequests) {
       if (v.destinationChainId === this.chainId) {
         added = true
-        this.useVoucher(v)
+        this.useVoucher(v.ref)
       }
     }
     assert(added, `No voucher requests found for chain ${this.chainId}`)
@@ -194,7 +199,8 @@ export class BatchBuilder {
   async createUserOp (): Promise<UserOperation> {
     const chainId = this.chainId
 
-    const smartAccount = this.smartAccount.contractOn(chainId)
+    const mcAccount = this.parentBuilder.getAccount()
+    const smartAccount = mcAccount.contractOn(chainId)
     const allCalls = await Promise.all(this.actions.map((action) => {
       return action.encodeCall(this)
     }))
@@ -209,14 +215,15 @@ export class BatchBuilder {
       smartAccount.getAddress(),
       smartAccount.getNonce(),
       smartAccount.getFactoryArgs(),
-      calls.length == 0 ? '0x' : this.smartAccount.encodeCalls(chainId, calls)
+      calls.length == 0 ? '0x' : mcAccount.encodeCalls(chainId, calls)
     ])
 
+    const nonce1 = BigInt(nowSeconds()) << 64n
     const { maxFeePerGas, maxPriorityFeePerGas } = await smartAccount.client.extend(publicActions).estimateFeesPerGas()
     let userOp = {
       chainId,
       sender,
-      nonce,
+      nonce: nonce1,
       factory,
       factoryData,
       callData,
@@ -312,7 +319,7 @@ export class BatchBuilder {
   }
 
   getVoucherInternalInfo (voucher: SdkVoucherRequest): InternalVoucherInfo | undefined {
-    return this.coordinator.getVoucherInternalInfo(voucher)
+    return this.coordinator.getVoucherInternalInfo(voucher.ref)
   }
 
   getOutVoucherRequests (): SdkVoucherRequest[] {
diff --git a/packages/sdk/src/sdk/builder/CrossChainBuilder.ts b/packages/sdk/src/sdk/builder/CrossChainBuilder.ts
index e3514d3..ec7cf14 100644
--- a/packages/sdk/src/sdk/builder/CrossChainBuilder.ts
+++ b/packages/sdk/src/sdk/builder/CrossChainBuilder.ts
@@ -15,7 +15,7 @@ import IEntryPointInterface from '@account-abstraction/contracts/artifacts/IEntr
 import { AtomicSwapFeeRule } from '../../contractTypes/AtomicSwapFeeRule.js'
 import { amountOrMinAmount, BatchBuilder } from './BatchBuilder.js'
 import { CrossChainExecutor } from './CrossChainExecutor.js'
-import { InternalConfig } from './InternalConfig.js'
+import { NetworkEnvironment } from './NetworkEnvironment.js'
 import {
   ICrossChainBuilder,
   InternalVoucherInfo,
@@ -55,10 +55,10 @@ export class CrossChainBuilder implements ICrossChainBuilder {
   private initialized = false
 
   batchBuilders: BatchBuilder[] = []
+  smartAccount: IMultiChainSmartAccount | undefined
 
   constructor (
-    readonly config: InternalConfig,
-    readonly smartAccount: IMultiChainSmartAccount,
+    readonly config: NetworkEnvironment,
   ) {
     this.ephemeralSigner = privateKeyToAccount(generatePrivateKey())
     this.coordinator = new CrossChainVoucherCoordinator()
@@ -66,17 +66,32 @@ export class CrossChainBuilder implements ICrossChainBuilder {
     this.feeConfig = { ...defaultFeeConfig, ...config.input.feeConfig ?? {} }
   }
 
+  useAccount (account: IMultiChainSmartAccount): this {
+    if (this.smartAccount != null) {
+      throw new Error('cannoot call useAccount() more than once')
+    }
+    this.smartAccount = account
+    return this
+  }
+
+  getAccount (): IMultiChainSmartAccount {
+    if (this.smartAccount == null) {
+      throw new Error('must call useAccount() before build')
+    }
+    return this.smartAccount
+  }
+
   /**
    * create a new batch, to be executed on the given chain.
-   * @param chainId
+   * @param chainId the chain this batch will be executed on.
    */
-  createBatch (chainId: bigint): BatchBuilder {
+  startBatch (chainId: bigint): BatchBuilder {
     this.assertNotBuilt()
     const batch = new BatchBuilder(
+      this,
       this.ephemeralSigner,
       this.coordinator,
       this.config,
-      this.smartAccount,
       this.config.paymasters.addressOn(chainId),
       chainId
     )
@@ -145,10 +160,12 @@ export class CrossChainBuilder implements ICrossChainBuilder {
         entryPointAddress: this.config.entrypoints.addressOn(batch.chainId)
       }
     })
+    let smartAccount = this.getAccount()
     for (const userOp of userOpsToSign) {
-      await this.smartAccount.verifyBundlerConfig(userOp.chainId!, userOp.entryPointAddress!)
+
+      await smartAccount.verifyBundlerConfig(userOp.chainId!, userOp.entryPointAddress!)
     }
-    const signedUserOps = await this.smartAccount.signUserOps(userOpsToSign)
+    const signedUserOps = await smartAccount.signUserOps(userOpsToSign)
 
     //update the signed users in the batches
     batches.forEach((batch, index) => {
@@ -228,8 +245,9 @@ export class CrossChainBuilder implements ICrossChainBuilder {
    * Call the paymaster's 'getSenderNonce' view function for the account.
    */
   async _getVoucherSenderNonce (chainId: bigint) {
+    let smartAccount = this.getAccount()
     return await this.config.paymasters.call(chainId,
-      'getSenderNonce', [this.smartAccount.addressOn(chainId)])
+      'getSenderNonce', [smartAccount.addressOn(chainId)])
   }
 
   /**
@@ -309,7 +327,7 @@ export class CrossChainBuilder implements ICrossChainBuilder {
   }
 
   getVoucherInternalInfo (voucher: SdkVoucherRequest): InternalVoucherInfo {
-    const info = this.coordinator.getVoucherInternalInfo(voucher)
+    const info = this.coordinator.getVoucherInternalInfo(voucher.ref)
     if (info == null) {
       throw new Error(`Voucher request ${voucher} not found in action builder`)
     }
@@ -321,8 +339,8 @@ export class CrossChainBuilder implements ICrossChainBuilder {
     const chainId = voucherInternalInfo.sourceBatch.chainId
     const allowedXlps = voucherInternalInfo.allowedXlps!
     const destChainId = voucherRequest.destinationChainId
-    const account = this.smartAccount.contractOn(chainId)
-    const destAccount = this.smartAccount.contractOn(destChainId)
+    const account = this.getAccount().contractOn(chainId)
+    const destAccount = this.getAccount().contractOn(destChainId)
     const paymaster = this.config.paymasters.addressOn(chainId)
     const destPaymaster = this.config.paymasters.addressOn(destChainId)
     return {
diff --git a/packages/sdk/src/sdk/builder/CrossChainExecutor.ts b/packages/sdk/src/sdk/builder/CrossChainExecutor.ts
index b1f8180..c483aa1 100644
--- a/packages/sdk/src/sdk/builder/CrossChainExecutor.ts
+++ b/packages/sdk/src/sdk/builder/CrossChainExecutor.ts
@@ -9,7 +9,7 @@ import {
   UserOperation
 } from '../types/index.js'
 import { CrossChainBuilder } from './CrossChainBuilder.js'
-import { InternalConfig } from './InternalConfig.js'
+import { NetworkEnvironment } from './NetworkEnvironment.js'
 import { SessionData } from '../../contractTypes/SessionData.js'
 import {
   abiEncodeVouchers,
@@ -101,7 +101,7 @@ export class CrossChainExecutor {
 
   constructor (
     readonly builder: CrossChainBuilder,
-    readonly config: InternalConfig,
+    readonly config: NetworkEnvironment,
     private readonly ephemeralSigner: PrivateKeyAccount,
     readonly batches: SingleChainBatch[],
     readonly timeoutSeconds = config.input.execTimeoutSeconds ?? 30,
@@ -197,9 +197,7 @@ export class CrossChainExecutor {
     const { userOp } = batchStatusInfo.batch
 
     this.watchForUserOperationEvents(batchStatusInfo, callback)
-    console.warn('sendUserOperation:')
-    console.warn(userOp)
-    this.builder.smartAccount.sendUserOperation(userOp as UserOperation)
+    this.builder.getAccount().sendUserOperation(userOp as UserOperation)
       .catch(e => {
         console.error('Error executing UserOperation:', e)
         // Validation failure during sending.
@@ -299,7 +297,7 @@ export class CrossChainExecutor {
     console.log(`watching VoucherIssued for ${sender}/${senderNonce} on chain ${chainId}`)
     const paymaster = this.config.paymasters.addressOn(chainId)
     const eventPoller = new EventsPoller({
-      client: this.config.chains.on(chainId),
+      client: this.config.chains.clientOn(chainId),
       abi: this.config.paymasters.abi,
       eventNames: ['VoucherIssued'],
       onLog: (log: any) => {
@@ -330,7 +328,7 @@ export class CrossChainExecutor {
     const VoucherRequestCreated = 'VoucherRequestCreated'
 
     const eventPoller: IEventPoller = new EventsPoller({
-      client: this.config.chains.on(chainId),
+      client: this.config.chains.clientOn(chainId),
       abi: [
         ...this.config.entrypoints.abi,
         ...this.config.paymasters.abi
diff --git a/packages/sdk/src/sdk/builder/CrossChainVoucherCoordinator.ts b/packages/sdk/src/sdk/builder/CrossChainVoucherCoordinator.ts
index b7b8f7e..5247f95 100644
--- a/packages/sdk/src/sdk/builder/CrossChainVoucherCoordinator.ts
+++ b/packages/sdk/src/sdk/builder/CrossChainVoucherCoordinator.ts
@@ -6,32 +6,32 @@ export class CrossChainVoucherCoordinator {
   /**
    * A mapping from the inputs of the Builder to the full voucher requests information for all batches.
    */
-  private vouchersInternalInfo: Map<SdkVoucherRequest, InternalVoucherInfo> = new Map()
+  private vouchersInternalInfo: Map<string, InternalVoucherInfo> = new Map()
 
   getAllVoucherInternalInfos (): InternalVoucherInfo[] {
     return [...this.vouchersInternalInfo.values()]
   }
 
-  getVoucherInternalInfo (sdkVoucherRequest: SdkVoucherRequest): InternalVoucherInfo | undefined {
-    return this.vouchersInternalInfo.get(sdkVoucherRequest)
+  getVoucherInternalInfo (refId: string): InternalVoucherInfo | undefined {
+    return this.vouchersInternalInfo.get(refId)
   }
 
   getAllOutVoucherRequests (): SdkVoucherRequest[] {
-    return Array.from(this.vouchersInternalInfo.keys())
+    return Array.from(this.vouchersInternalInfo.values()).map(info => info.voucher)
   }
 
   has (sdkVoucherRequest: SdkVoucherRequest): boolean {
-    return this.vouchersInternalInfo.has(sdkVoucherRequest)
+    return this.vouchersInternalInfo.has(sdkVoucherRequest.ref)
   }
 
-  set (sdkVoucherRequest: SdkVoucherRequest, internalVoucherInfo: InternalVoucherInfo): void {
-    this.vouchersInternalInfo.set(sdkVoucherRequest, internalVoucherInfo)
+  set (internalVoucherInfo: InternalVoucherInfo): void {
+    this.vouchersInternalInfo.set(internalVoucherInfo.voucher.ref, internalVoucherInfo)
   }
 
   updateVoucherXlps (voucherReq: SdkVoucherRequest, xlps: Address[]) {
-    const info = this.vouchersInternalInfo.get(voucherReq)
+    const info = this.vouchersInternalInfo.get(voucherReq.ref)
     if (!info) {
-      throw new Error(`Voucher request ${voucherReq} not found in action builder`)
+      throw new Error(`Voucher request ${voucherReq.ref} not found in action builder`)
     }
     info.allowedXlps = xlps
   }
diff --git a/packages/sdk/src/sdk/builder/MultichainBundlerManager.ts b/packages/sdk/src/sdk/builder/MultichainBundlerManager.ts
index 1bbebec..b4a0e4b 100644
--- a/packages/sdk/src/sdk/builder/MultichainBundlerManager.ts
+++ b/packages/sdk/src/sdk/builder/MultichainBundlerManager.ts
@@ -1,5 +1,4 @@
 import { Address, createClient, fromHex, Hex, http } from 'viem'
-import { entryPoint08Address } from 'viem/account-abstraction'
 
 import { stringifyBigIntReplacer } from '../sdkUtils/SdkUtils.js'
 import { IBundlerManager } from '../types/IBundlerManager.js'
@@ -8,31 +7,16 @@ import { UserOperation } from '../types/UserOperation.js'
 import { IJsonRpcProvider } from '../types/index.js'
 
 export class MultichainBundlerManager implements IBundlerManager {
-  isInitialized = false
 
-  constructor (readonly chainInfos: ChainInfo[], bundlers: Array<[chainId: bigint, url: string, entryPoint?: Address]> = []) {
-    for (const [chainId, url, entryPointAddress] of bundlers) {
+  constructor (readonly chainInfos: ChainInfo[]) {
+    for (const { chainId, bundlerUrl, entryPointAddress } of chainInfos) {
       let provider = createClient({
-        transport: http(url, { retryCount: 0 })
+        transport: http(bundlerUrl, { retryCount: 0 })
       }).transport
-      this.addBundler(chainId, provider, entryPointAddress ?? entryPoint08Address)
-    }
-  }
-
-  async initialize (): Promise<void> {
-    for (const chain of this.chainInfos) {
-      let provider: IJsonRpcProvider
-      if (chain.bundlerUrl != null) {
-        provider = createClient({
-          transport: http(chain.bundlerUrl, { retryCount: 0 })
-        }).transport
-      } else {
-        provider = chain.publicClient.transport
+      if (bundlerUrl !== undefined) {
+        this.addBundler(chainId, provider, entryPointAddress!)
       }
-      const entryPointAddress = chain.entryPointAddress ?? entryPoint08Address
-      this.addBundler(chain.chainId, provider, entryPointAddress)
     }
-    this.isInitialized = true
   }
 
   bundlers: Map<bigint, IJsonRpcProvider> = new Map()
@@ -59,9 +43,6 @@ export class MultichainBundlerManager implements IBundlerManager {
   }
 
   sendUserOperation (userOp: UserOperation): Promise<Hex> {
-    if (!this.isInitialized) {
-      throw new Error('MultichainBundlerManager is not initialized')
-    }
     const provider = this.bundlers.get(userOp.chainId!)!
     if (!provider) {
       throw new Error(`No bundler found for chainId: ${userOp.chainId!}`)
@@ -69,7 +50,7 @@ export class MultichainBundlerManager implements IBundlerManager {
     const jsonUserOp = JSON.parse(JSON.stringify(userOp, stringifyBigIntReplacer))
     return provider.request({
       method: 'eth_sendUserOperation',
-      params: [jsonUserOp, this.entryPoints.get(userOp.chainId!)]
+      params: [jsonUserOp, userOp.entryPointAddress]
     })
   }
 }
diff --git a/packages/sdk/src/sdk/builder/InternalConfig.ts b/packages/sdk/src/sdk/builder/NetworkEnvironment.ts
similarity index 78%
rename from packages/sdk/src/sdk/builder/InternalConfig.ts
rename to packages/sdk/src/sdk/builder/NetworkEnvironment.ts
index 8fd5c01..cf1fd00 100644
--- a/packages/sdk/src/sdk/builder/InternalConfig.ts
+++ b/packages/sdk/src/sdk/builder/NetworkEnvironment.ts
@@ -1,16 +1,13 @@
-import { MultichainContract } from '../types/index.js'
-import { MultichainClient } from '../types/index.js'
+import { entryPoint09Address, MultichainClient, MultichainContract } from '../types/index.js'
 import { EntryPointMeta, ICrossChainPaymaster } from '../../abitypes/abiTypes.js'
-import { entryPoint09Address } from '../types/Constants.js'
 import { CrossChainConfig } from '../config/index.js'
-import { getMultiChainConfig } from './GetMultiChainConfig.js'
 
 /**
  * Parses input configuration into configuration objects used by the builder and executor.
  * This includes setting up chain clients, paymasters, bundlers, and entry points across multiple chains.
  * @see {CrossChainConfig} for input configuration structure.
  */
-export class InternalConfig {
+export class NetworkEnvironment {
 
   readonly chains: MultichainClient
   readonly paymasters: MultichainContract
@@ -20,7 +17,7 @@ export class InternalConfig {
     readonly input: CrossChainConfig
   ) {
     this.chains = new MultichainClient()
-    const chains = getMultiChainConfig(this.input.chainsInfoOverride)
+    const chains = this.input.chainInfos
 
     chains.forEach(chain => {
       this.chains.addClientWithChainId(chain.publicClient, BigInt(chain.chainId))
diff --git a/packages/sdk/src/sdk/builder/index.ts b/packages/sdk/src/sdk/builder/index.ts
index b479afb..934bc14 100644
--- a/packages/sdk/src/sdk/builder/index.ts
+++ b/packages/sdk/src/sdk/builder/index.ts
@@ -3,7 +3,7 @@ export * from './BatchBuilder.js'
 export * from './CrossChainBuilder.js'
 export * from './CrossChainExecutor.js'
 export * from './CrossChainVoucherCoordinator.js'
-export * from './InternalConfig.js'
 export * from './MultichainBundlerManager.js'
 export * from './GetMultiChainConfig.js'
+export * from './NetworkEnvironment.js'
 
diff --git a/packages/sdk/src/sdk/config/CrossChainConfig.ts b/packages/sdk/src/sdk/config/CrossChainConfig.ts
index 249b039..d30382f 100644
--- a/packages/sdk/src/sdk/config/CrossChainConfig.ts
+++ b/packages/sdk/src/sdk/config/CrossChainConfig.ts
@@ -3,6 +3,7 @@ import { XlpSelectionConfig } from './XlpSelectionConfig.js'
 import { FeeConfig } from './FeeConfig.js'
 import { ChainInfo } from './ChainInfo.js'
 import { PaymasterActions } from 'viem/account-abstraction'
+import { getMultiChainConfig } from '../builder/index.js'
 
 // general config of the CrossChainSdk
 export type CrossChainConfig = {
@@ -22,7 +23,13 @@ export type CrossChainConfig = {
   execTimeoutSeconds: number
 
   /**
-   * override default chain configuration (urls and contracts)
+   * per-chain info (urls, contracts)
    */
-  chainsInfoOverride?: ChainInfo[]
+  chainInfos: ChainInfo[]
+}
+
+export const defaultCrossChainConfig: CrossChainConfig = {
+  expireTimeSeconds: 60,
+  execTimeoutSeconds: 30,
+  chainInfos: getMultiChainConfig()
 }
diff --git a/packages/sdk/src/sdk/types/Constants.ts b/packages/sdk/src/sdk/types/Constants.ts
index 862d78d..850735d 100644
--- a/packages/sdk/src/sdk/types/Constants.ts
+++ b/packages/sdk/src/sdk/types/Constants.ts
@@ -4,4 +4,4 @@ export const Hex0x: Hex = '0x'
 
 export const NATIVE_ETH: Address = '0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE'
 
-export const entryPoint09Address: Address = '0x433709009B8330FDa32311DF1C2AFA402eD8D009'
+export const entryPoint09Address: Address = '0x43370900c8de573dB349BEd8DD53b4Ebd3Cce709'
diff --git a/packages/sdk/src/sdk/types/ICrossChainBuilder.ts b/packages/sdk/src/sdk/types/ICrossChainBuilder.ts
index bc25152..dcd67e8 100644
--- a/packages/sdk/src/sdk/types/ICrossChainBuilder.ts
+++ b/packages/sdk/src/sdk/types/ICrossChainBuilder.ts
@@ -1,6 +1,7 @@
 import { BatchBuilder, CrossChainExecutor } from '../builder/index.js'
 import { SingleChainBatch } from './SingleChainBatch.js'
 import { UserOperation } from './UserOperation.js'
+import { IMultiChainSmartAccount } from '../account/index.js'
 
 export interface ICrossChainBuilder {
 
@@ -8,7 +9,13 @@ export interface ICrossChainBuilder {
    * create a new batch, to be executed on the given chain.
    * @param chainId
    */
-  createBatch (chainId: bigint): BatchBuilder;
+  startBatch (chainId: bigint): BatchBuilder;
+
+  /**
+   * set the account to use to build and execution that coross chain operation
+   * must be called before build() and sign()
+   */
+  useAccount(account: IMultiChainSmartAccount): this
 
   /**
    * Build an array of {@link SingleChainBatch} objects, ready to be signed
@@ -24,6 +31,8 @@ export interface ICrossChainBuilder {
    */
   buildAndSign (): Promise<CrossChainExecutor>;
 
+  getAccount(): IMultiChainSmartAccount
+
   /**
    * initialize the SDK. validate all configuration is correct.
    */
diff --git a/packages/sdk/src/sdk/types/ICrossChainSdk.ts b/packages/sdk/src/sdk/types/ICrossChainSdk.ts
index 85b0e0d..f83b9bc 100644
--- a/packages/sdk/src/sdk/types/ICrossChainSdk.ts
+++ b/packages/sdk/src/sdk/types/ICrossChainSdk.ts
@@ -1,4 +1,7 @@
 import { ICrossChainBuilder } from './ICrossChainBuilder.js'
+import { AddressPerChain } from './MultichainContract.js'
+import { MultichainToken } from './MultichainToken.js'
+import { NetworkEnvironment } from '../builder/index.js'
 
 /**
  * CrossChainSdk is the main entry point for building cross-chain actions.
@@ -10,5 +13,12 @@ export interface ICrossChainSdk {
    * create a builder for a cross-chain operation
    */
   createBuilder (): ICrossChainBuilder
+
+  /**
+   * create a MultichainToken with the given deployment addresses
+   */
+  createToken (name: string, deployments: AddressPerChain): MultichainToken
+
+  getNetworkEnv(): NetworkEnvironment
 }
 
diff --git a/packages/sdk/src/sdk/types/MultichainClient.ts b/packages/sdk/src/sdk/types/MultichainClient.ts
index ec487bf..1f8f45d 100644
--- a/packages/sdk/src/sdk/types/MultichainClient.ts
+++ b/packages/sdk/src/sdk/types/MultichainClient.ts
@@ -33,7 +33,7 @@ export class MultichainClient {
     this.clients.set(chainId, client);
   }
 
-  on (chainId: bigint): PublicClient {
+  clientOn (chainId: bigint): PublicClient {
     if (!this.clients.has(chainId)) {
       throw new Error(`No client found for chainId: ${chainId}. Supported chains: ${Array.from(this.clients.keys()).join(', ')}`);
     }
@@ -48,7 +48,7 @@ export class MultichainClient {
     args: any[],
     value?: bigint
   }): Promise<any> {
-    const client = this.on(chainId);
+    const client = this.clientOn(chainId);
     const data = encodeFunctionData({ abi, functionName, args });
     const valueHex = value ? toHex(value) : undefined
     const ret = await client.request({ method: 'eth_call', params: [{ to, data, value: valueHex }, 'latest'] }) as Hex
diff --git a/packages/sdk/src/sdk/types/MultichainContract.ts b/packages/sdk/src/sdk/types/MultichainContract.ts
index 7928b4f..d746b56 100644
--- a/packages/sdk/src/sdk/types/MultichainContract.ts
+++ b/packages/sdk/src/sdk/types/MultichainContract.ts
@@ -67,7 +67,7 @@ export class MultichainContract implements IMultiChainEntity {
   }
 
   async call (chainId: bigint, functionName: string, args: any[], callOptions: any = {}): Promise<any> {
-    const client = this.client.on(chainId)
+    const client = this.client.clientOn(chainId)
     const data = this.encodeFunctionData(functionName, args)
     const ret = await client.call({
       to: this.addressOn(chainId),
diff --git a/packages/sdk/src/sdk/types/MultichainToken.ts b/packages/sdk/src/sdk/types/MultichainToken.ts
index 45c6f4c..5eaa207 100644
--- a/packages/sdk/src/sdk/types/MultichainToken.ts
+++ b/packages/sdk/src/sdk/types/MultichainToken.ts
@@ -11,7 +11,7 @@ export type TotalBalanceOfResult = {
 
 //wrapper for multichain ERC20 token operations.
 export class MultichainToken extends MultichainContract {
-  constructor (client: MultichainClient, deployments: AddressPerChain) {
+  constructor (name: string, client: MultichainClient, deployments: AddressPerChain) {
     super(client, erc20Abi, deployments)
   }
 
diff --git a/packages/sdk/src/sdk/types/SdkVoucherRequest.ts b/packages/sdk/src/sdk/types/SdkVoucherRequest.ts
index 78bbb6c..1d0cc10 100644
--- a/packages/sdk/src/sdk/types/SdkVoucherRequest.ts
+++ b/packages/sdk/src/sdk/types/SdkVoucherRequest.ts
@@ -10,4 +10,7 @@ export interface SdkVoucherRequest {
   target?: Address
   sourceChainId?: bigint
   destinationChainId: bigint
+
+  // internal ID used during batch building. must be unique.
+  ref: string
 }
diff --git a/packages/sdk/src/utils/getSolventXlps.ts b/packages/sdk/src/utils/getSolventXlps.ts
index d390606..91f31bb 100644
--- a/packages/sdk/src/utils/getSolventXlps.ts
+++ b/packages/sdk/src/utils/getSolventXlps.ts
@@ -61,7 +61,7 @@ export async function getSolventXlps (
   length: number = 1000
 ): Promise<SolventXlpInfo[]> {
   const paymasterAddress: Address = paymasters.addressOn(chainId)
-  const client: PublicClient = paymasters.client.on(chainId)
+  const client: PublicClient = paymasters.client.clientOn(chainId)
   const assets: Asset[] = mcAssets.map((asset: MultiChainAsset) => ({
     erc20Token: toAddress(chainId, asset.token),
     amount: amountOrMinAmount(asset)
diff --git a/yarn.lock b/yarn.lock
index ab6e555..9a50703 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1254,6 +1254,11 @@ p-map@^7.0.2:
   resolved "https://registry.yarnpkg.com/p-map/-/p-map-7.0.4.tgz#b81814255f542e252d5729dca4d66e5ec14935b8"
   integrity sha512-tkAQEw8ysMzmkhgw8k+1U/iPhWNhykKnSk4Rd5zLoPJCuJaGRPo6YposrZgaxHKzDHdDWWZvE/Sk7hsL2X/CpQ==
 
+permissionless@^0.3.2:
+  version "0.3.2"
+  resolved "https://registry.yarnpkg.com/permissionless/-/permissionless-0.3.2.tgz#334398236c7b2747dddbf78509471af03f8fba51"
+  integrity sha512-/YlcuybrW9ph+IQ0/vwRWZooEElXnsEgvXLJ/+HA1iU0kwIeTcxx4xlA6TiVZ/zTTsovS3+cSgVa8n7Sz/oTXg==
+
 pretty-format@^29.7.0:
   version "29.7.0"
   resolved "https://registry.yarnpkg.com/pretty-format/-/pretty-format-29.7.0.tgz#ca42c758310f365bfa71a0bda0a807160b776812"
@@ -1422,9 +1427,9 @@ viem@^2.39.0:
     ws "8.18.3"
 
 viem@^2.39.2:
-  version "2.39.2"
-  resolved "https://registry.yarnpkg.com/viem/-/viem-2.39.2.tgz#c8f747bf22ae2ca46011a8e8ae22f26085ae3fba"
-  integrity sha512-EJPt+T0AkMxKvBRPFHYMLMuvcHiIhoYItkioHRGCkkm6LBSwlK6l9DNzoKA9S09LP003BiMeYddVjVso+lg2Og==
+  version "2.39.3"
+  resolved "https://registry.yarnpkg.com/viem/-/viem-2.39.3.tgz#45884cc27d3faced1fc1d293fc2d9018b8b0789f"
+  integrity sha512-s11rPQRvUEdc5qHK3xT4fIk4qvgPAaLwaTFq+EbFlcJJD+Xn3R4mc9H6B6fquEiHl/mdsdbG/uKCnYpoNtHNHw==
   dependencies:
     "@noble/curves" "1.9.1"
     "@noble/hashes" "1.8.0"